Circuits formed in semiconductor devices utilize a power supply, called V.sub.CC, and a ground. Electrical connection is made to V.sub.CC and ground through metal lines in the circuits. The metal lines are typically formed in layers. The lines to V.sub.CC and ground are designed to be connected only through the circuits. However, the lines between V.sub.CC and ground may be shorted. When V.sub.CC is shorted to ground, the circuits in the semiconductor device do not function. Thus, detection of these shorts is desirable.
One conventional method for detecting shorts uses liquid crystals. A layer of a liquid crystal is poured on a surface of the device and power provided to the circuits of the device. The V.sub.CC to ground shorts may generate heat. The heat generated may cause the liquid crystal to change phase or move. Thus, the positions of the shorts in the plane of the semiconductor device may be determined. Another conventional method for detecting shorts deprocesses the semiconductor device in which the power supply, V.sub.CC, is shorted to ground. As the device is deprocessed layer by layer, each metal layer is investigated to determine if the short exists between lines in that layer. When the short is found, the information can be provided to those fabricating the device, and fabrication changed to reduce the likelihood of shorts.
Although the conventional methods can detect shorts, they are difficult to perform and time consuming. Liquid crystal detection requires careful control of the thickness of the liquid crystal. Liquid crystal also does not reveal in which metal layer the short is located. Thus, deprocessing may still be required. In addition, liquid crystal detection may not be capable of locating shorts which are relatively far from the surface on which the liquid crystal is placed because heat is dissipated in the device. Conventional deprocessing is also time consuming. In addition, deprocessing may inadvertently destroy the short. Thus, many semiconductor devices may need to be investigated before the location of the V.sub.CC to ground short can be found. Thus, conventional methods for locating V.sub.CC to ground shorts are time consuming and difficult to perform. Thus, it may take a relatively long time to be able to change the processes in fabrication which cause the shorts.
Accordingly, what is needed is a system and method for easily and rapidly detecting V.sub.CC to ground shorts. The present invention addresses such a need.